Due to the geographical situation in central Europe, the density of road and rail tunnels is extremely high compared to other parts of the world. These bridges were mainly constructed with concrete building material in conjunction with reinforcing bars. Natural ageing (“carbonation“) and environmental factors such as static overloading or salt spreading are primary sources of damage to the concrete and reinforcement. Ensuring the safety of the tunnel requires timely and professional concrete repairs. For this purpose, the old concrete is removed so that reinforcing rods can be exposed and cleaned. A new corrosion protection system can then be applied, followed by a new top layer of concrete and a special coating.

The advantage of removing concrete with high-pressure water jets is that surfaces are treated gently and without vibrations, which prevents stress cracks. At the same time, the reinforcement is cleaned directly by the water jet and prepared for further processing steps.

Damaged concrete is partially removed with a water jet at up to 3000bar and 400 litres per minute; this is done by special removal robots, or manually by way of hand lances.